Re: [PATCH V4 6/8] perf/x86/intel/uncore: SKX support for IIO free running counters

From: Thomas Gleixner
Date: Sun Jan 14 2018 - 15:54:58 EST


On Thu, 2 Nov 2017, kan.liang@xxxxxxxxx wrote:

> From: Kan Liang <Kan.liang@xxxxxxxxx>
>
> As of Skylake Server, there are a number of free-running counters in
> each IIO Box that collect counts for per box IO clocks and per Port
> Input/Output x BW/Utilization.
>
> The free running counter is read-only and always active. Counting will
> be suspended only when the IIO Box is powered down.
>
> There are three types of IIO free running counters on Skylake server, IO
> CLOCKS counter, BANDWIDTH counters and UTILIZATION counters.
> IO CLOCKS counter is to count IO clocks.
> BANDWIDTH counters are to count inbound(PCIe->CPU)/outbound(CPU->PCIe)
> bandwidth.
> UTILIZATION counters are to count input/output utilization.
>
> The bit width of the free running counters is 36-bits.
>
> Signed-off-by: Kan Liang <Kan.liang@xxxxxxxxx>

Assumed that all the magic numbers are correct:

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>